Hi. I'm a female and was 47 with the same type of cancer and treatment. Go see a PT that does stain-counterstrain. This treatment helped me right away. (I did not have pain, but couldn't swallow.) I bet they could help with the pain as well. It is important though that the PT know the counterstain technique.
Also.....find stretching exercises that will help with neck stiffness later. I wish I had done this. No told me to, and now 4 years post treatment, I'm dealing with horrible stiffness that causing pretty tough issues for me. Do the stretching exercises the rest of your life to prevent or reduce the horrible tightening of your neck. You will thank yourself!!!!